Just checked with son's partner who says they ended up getting insurance via a broker and it is some type of construction insurance, because they will be having a builder do a renovation, signing a contract with a builder etc.
Our son could not get insurance on his new PPOR because it had no kitchen or bathrooms. It is not an easy thing to get.
I know my concern was more that it meant no public liability insurance.
Why not call a broker and see what he/she can do for you?